id:A107913 - OEIS Search Results

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Numbers n that require three iterations of the sigma function to be >= 2n.

+0
4

9, 13, 25, 37, 43, 49, 61, 67, 73, 97, 109, 121, 151, 157, 163, 169, 181, 193, 211, 225, 229, 241, 277, 283, 289, 313, 331, 337, 361, 373, 397, 409, 421, 433, 457, 487, 523, 529, 541, 547, 577, 601, 613, 625, 631, 661, 673, 691, 709, 729, 733, 751, 757, 787 (list; graph; listen)

	OFFSET	`0,1`
	REFERENCES	`Cf. A000203, A055021, A107912, A107914.`
	EXAMPLE	`Sigma(Sigma(9))=14 but Sigma(Sigma(Sigma(9)))=24, so 9 is in the sequence.`
	CROSSREFS	`Sequence in context: A033870 A144933 A097539 this_sequence A098074 A032361 A031196` `Adjacent sequences: A107910 A107911 A107912 this_sequence A107914 A107915 A107916`
	KEYWORD	`nonn`
	AUTHOR	`Jud McCranie (j.mccranie(AT)comcast.net), May 27 2005`

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Last modified December 4 15:51 EST 2008. Contains 151308 sequences.

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